How to make Vim detect filetype from the shebang line? - bash

Sometimes I write scripts without any filename extension. For example:
#!/usr/bin/env node
console.log('hello world!');
I hope that Vim can detect the filetype from the shebang line (e.g. #!/usr/bin/env node is javascript). What should I put into filetype.vim?

Following the instructions listed in :help new-filetype-scripts,
create the scripts.vim file in the user runtime directory (~/.vim/
on Unix-like systems), and write the following script in it:
if did_filetype()
finish
endif
if getline(1) =~# '^#!.*/bin/env\s\+node\>'
setfiletype javascript
endif

create this file ~/.vim/ftdetect/node.vim
with this contents
fun! s:DetectNode()
if getline(1) == '#!/usr/bin/env node'
set ft=javascript
endif
endfun
autocmd BufNewFile,BufRead * call s:DetectNode()

If you're interested in a plugin, one does exist for this:
https://github.com/vitalk/vim-shebang
This contains a pattern for node -> javascript highlighting.
AddShebangPattern! javascript ^#!.*\s\+node\>

A little late to the party, but Node.vim handles detecting such JavaScript files for you. And then some. :-)

Related

Which function of V8 engine print informations to stdout?

I add flag “--print-opt-code” to V8 engine, then v8 could print the compiled code to stdout. And now I what to print these information to specific files, then which function should I modify?
Thank you very much~~
Try this: --redirect-code-traces-to=<filename> ;-)
Generally speaking: follow the FLAG_print_opt_code through the source and see what it does.
Depending on where you run V8 (in d8? in Chrome? in node.js?), it might be easiest to just use shell redirection: .../d8 test.js --print-opt-code > output.txt

shell cd command in Ruby

Im trying to execute shell commands using ruby, but i cant change directory to PATH with blank spaces.
variable = %x[cd #{ENV["HOME"]}/Virtual\\ VMs/]
This is not working.
Thank you
To be absolutely safe:
path = File.join [ENV["HOME"], 'Virtual VMs']
variable = %x[cd '#{path}']
Please note, that cd has empty output, so to make sure it works one probably wants to do smth like:
path = File.join [ENV["HOME"], 'Virtual VMs']
variable = %x[cd '#{path}' && ls -la]
#⇒ "total 32\ndrwxr-xr-x ....."
What is ist supposed to do? You try to chdir into a directory, but then don't do anything in it. Your variable will be empty in any case. Aside from the fact that it is pointless to do, you can not reliably execute a cd by itself in this way, because it is not an executable file. You can see this if you just execute %x[cd]. You will get an Errno::ENOENT exception.
Maybe you should first describe in a broader context, what you want to achieve with your code. Where would you like to change the working directory? Within the Ruby process - in which case you have to use Dir.chdir - or in the child process - in which case you have to execute some command after the cd.

Vim slow with ruby syntax highlighting

I've been using vim over ssh to work for a week or two now and all has been going great. Today I decided to add in some syntax highlighting, autocomplete, and some other general plugins. Set up vundle and went to work.
My current .vimrc can be found at https://github.com/scottopell/dotfiles/blob/master/.vimrc
I have cloned my vimrc and vim files onto my local ubuntu desktop and vim runs exactly as expected, no slowness on any files that I can find. Same plugins and same vimrc and no slowness on ruby files.
update
I can reproduce this issue with the following .vimrc
syntax on
and an empty ~/.vim folder.
However, vim on this vps is very slow with ruby/haml files. Much moreso ruby files. When I open any ruby file, startup takes about 2 seconds (timed with --startuptime). With a comparable length haml file, its about .5 seconds. This slowness isn't just on startup either, moving around and editing the file are both painfully slow.
Haml/erb(they are basically the same)
268.818 000.005: before starting main loop
848.871 580.053: first screen update
Ruby
199.613 000.004: before starting main loop
2937.859 2738.246: first screen update
Without syntax highlighting on the same ruby file as above
149.047 000.004: before starting main loop
152.912 003.865: first screen update
I have tried using mosh(http://mosh.mit.edu) and it doesn't help. not really relevant anymore
As you can see in my .vimrc file, I have tried a few different solutions to this problem.
I have tried running with all plugins disabled (I moved them all from ~/vim/bundle/PLUGINNAME to ~/vim/bundle/disabled/PLUGINNAME, is this correct?), set ruby path, set foldlevel to manual, disabled my colorscheme, nothing helps. see edit3
I can post the full startupttime log for any file if that will help.
I have tested a few other languages(php, c, python, vimL) and none experience any slowdown.
EDIT: Just to clarify, I am running an ssh session with ssh user#server then once inside the server I am doing vim file.rb.
EDIT2: I just tried accessing the server directly and the slowness persists without ssh, I have updated to reflect that this isn't a problem with ssh.
EDIT3: I can reproduce the issue with a .vimrc file that contains the single line syntax on with an empty ~/.vim folder
EDIT4 I uninstalled my compiled version of vim and any versions that I may have installed through apt, manually removed all vim stuff from my system, and I can run vim with vim -u NONE /path/to/file.rb then do :syn on and the issue will be there. The file in question is a rails controller, but like I've said, I can recreate it to some degree with most any file, but rails controllers see to be the worst.
The solution to this problem turned out to be the regex engine that vim uses.
The speculation on #vim on freenode is that the ruby syntax files use something that is slower on the new regex engine.
Any version older than and including Vim 7.3.969 has the old regex engine.
Add in set re=1 to your vimrc to force the old regex engine on any version newer (and don't forget to reload the file you're currently editing with :e).
Thanks to Houl, Dolio and dmedvinsky from #vim for help figuring it out.
I haven't had a chance to try the absolute latest version, there was a commit last night that may help with this issue. I will update this if I get the chance to try the bleeding edge version again.
You should set this tw options in your vimrc:
set ttyfast
set lazyredraw
If this is not solving your problem try to start vim without your vimrc to be sure that none of your current settings are screwing it up.
vim -u NONE
Two things that will drastically help speed up Ruby syntax highlighting are disabling cursor line and relative number for Ruby (if you use those).
I have the following in my .vimrc:
" Ruby is an oddball in the family, use special spacing/rules
if v:version >= 703
" Note: Relative number is quite slow with Ruby, so is cursorline
autocmd FileType ruby setlocal ts=2 sts=2 sw=2 norelativenumber nocursorline
else
autocmd FileType ruby setlocal ts=2 sts=2 sw=2
endif
I'm using vim 7.4.52 and none of these solutions worked for me.
According to this github comment on the issue (https://github.com/vim/vim/issues/282#issuecomment-169837021), foldmethod=syntax is responsible for the slowness.
Adding this to my .vimrc finally fixed it!
augroup ft_rb
au!
" fix the SLOOOW syntax highlighting
au FileType ruby setlocal re=1 foldmethod=manual
augroup END
Try setting your ruby path explicitly in your vimrc:
let g:ruby_path="/usr/bin/ruby"
see UPDATE at the bottom.
this may be helpful as a workaround -
i am using vim version
VIM - Vi IMproved 7.4 (2013 Aug 10, compiled Jan 2 2014 19:40:46)
Included patches: 1-52
it is the stock version from
Linux Mint 17.1 Rebecca.
the php.vim syntax file is not version'd that i can see, but it sez last edit'd 28 aug 13.
it isn't a ruby project, but when editing a large php class file (
$ php -w test.inc | wc
2 2410 19220
) i note significant delays near the top of the class, but not above or below the class, and, notably, not toward the bottom of the class. as i attempt to insert new text near the bottom of the class, delay is minimal and seems to be proportional to the line number inside the class. "minimal" means almost instantly, "significant" means 1 to 1.5 seconds per character.
the file is approx 1800 lines with approx 500 lines of legit php and 1300 lines of comments and doc. the class begins at approx line 30 and ends at approx line 1700. it is conceded it's a bit large, but well documented :-\
if i insert
class dummy { }
in front of the original "class originalName {",
there is no delay anywhere in the file. this unsightly kluge permits vim/gvim to regain its responsiveness and could be considered a workaround. note no linefeed between the two, just
class dummy { } class originalName {
it can even be comment'd out:
/*class dummy {}*/class originalName {
additional info:
during this test, the plugins directory was moved.
with "set syntax=off", the problem completely disappears. this is NOT a fix.
setting the regular expression engine with
set regexpengine=1 (or any other number)
does not appreciably change the results.
based on these results, i would suspect the regular expression engine as well. my point is that diddling a bit with the syntax in ruby files may lead to a workaround.
UPDATE:
i have found that the issue is "caused" by setting php_folding to 1 (enabled). the vimrc i THOUGHT i was using was not, but at least some of the mystery is solved due to that mistake. a simple vimrc like this will induce the problem (for me, as least):
:syntax enable
:let php_folding = 1
this means my issue is totally unrelated to the ruby issue, but there may be a similar thing going on with the ruby.vim file. maybe not.
apologies for the deflection.
I tried most of these solutions but what ended up working for me the best was removing any plugins associated with airline.

Is there a Vim plugin for Ruby which provides a "switch to/from test" command outside of Rails?

Tim Pope's rails.vim provides a command :A (and a set of related commands) which opens the "alternate" file. For most classes, that's the test, and for the test, the class.
It would sure be nice to have that functionality in non-Rails Ruby projects. Is there a plugin which provides that? Bonus points if it helps me create the test file when I create the implementation file. :)
Our hero tpope wrote rake.vim too. It does the very same things rails.vim does but in Ruby projects.
I created the following command that makes it possible to do
:E /pattern/replace
to jump to the file that is the current filename and substituting pattern by replace
For example, if your tests files are in /test/code.js and your src files in /src/code.js you could write the following command:
command! -nargs=* Es :call EditSubstitute("/test/src")
command! -nargs=* Et :call EditSubstitute("/src/test")
to have the command :Es to jump from testfile to source file and the command :Et to jump from source file to testfile.
Here's the function that does that :
function! EditSubstitute(args)
if (len(a:args))<2
return
endif
let s:delimiter = (a:args[0])
let s:split = split(a:args,s:delimiter,1)[1:]
let s:fullpath = expand('%:p')
let s:bar = substitute(s:fullpath, s:split[0], s:split[1], "")
echo (s:bar)
silent execute('edit '.s:bar)
endfunction
command! -nargs=* E :call EditSubstitute(<q-args>)
I know this doesn't really answer your question at all... but I use VIM buffers to provide easy accessibility to a file and its tests.
I keep my test on top, and the file on the bottom. Then I can view both at the same time.
I use NERDTree to make browsing easier too, but that is not a per-requisite.
You can get a full reference of what I use here:
https://github.com/coderjoe/dotfiles
If you like it I'd recommend NOT using my dotfiles from the above repo, but start with something like RyanB's dotfiles and build your own sets based on your own preferences. :)
Have a look at the vimrc of the guy from 'Destroy all software' https://github.com/garybernhardt/dotfiles/blob/master/.vimrc#L280
pressing <leader>. will switch you between your code and the spec code.
-frbl

How can I include Win32 modules only when I'm running my Perl script on Windows?

I have a problem that I cannot seem to find an answer to.
With Perl I need to use a script across Windows and unix platforms. Te problem is that on Windows we use Win32-pecific modules like Win32::Process, and those modules do not exist on unix.
I need a way to include those Win32 modules only on Windows.
if($^O =~ /win/i)
{
use win32::process qw(CREATE_NEW_CONSOLE);
}
else
{
#unix fork
}
The problem lies in that use statement for windows. No matter what I try this does not compile on unix.
I have tried using dynamic evals, requires, BEGIN, etc.
Is there a good solution to this problem? Any help will be greatly appreciated.
Thanks in advance,
Dan
Update:
A coworker pointed out to me this is the correct way to do it.
require Win32;
require Win32::Process;
my $flag = Win32::Process::CREATE_NEW_CONSOLE();
Win32::Process::Create($process,
$program,
$cmd,
0,
$flag, ".") || die ErrorReport();
print "Child started, pid = " . getPID() . "\n";
Thank you all for your help!
Dan
use is executed at compile time.
Instead do:
BEGIN {
if( $^O eq 'MSWin32' ) {
require Win32::Process;
# import Win32::Process qw(CREATE_NEW_CONSOLE);
Win32::Process->import(qw/ CREATE_NEW_CONSOLE /);
}
else {
#unix fork
}
}
See the perldoc for use.
Also see perlvar on $^O.
Update:
As Sinan Unur points out, it is best to avoid indirect object syntax.
I use direct method calls in every case, except, with calls to import. Probably because import masquerades as a built-in. Since import is really a class method, it should be called as a class method.
Thanks, Sinan.
Also, on Win32 systems, you need to be very careful that you get the capitalization of your module names correct. Incorrect capitalization means that symbols won't be imported properly. It can get ugly.use win32::process may appear to work fine.
Are you sure win32::process can be loaded on OSX? "darwin" matches your /win/i.
You may want to use http://search.cpan.org/dist/Sys-Info-Base/ which tries to do the right thing.
That aside, can you post an example of the code that you actually are using, the failure message you're receiving, and on which unix platform (uname -a) ?
What about a parser that modifies the file on each OS?
You could parse your perl file via a configure script that works on both operating systems to output perl with the proper Use clauses. You could even bury the parse action in the executable script to launch the code.
Originally I was thinking of precompiler directives from C would do the trick, but I don't know perl very well.
Here's an answer to your second set of questions:
Are you using strict and warnings?
Did you define an ErrorReport() subroutine? ErrorReport() is just an example in the synopsis for Win32::Process.
CREATE_NEW_CONSOLE is probably not numeric because it didn't import properly. Check the capitalization in your call to import.
Compare these one-liners:
C:\>perl -Mwin32::process -e "print 'CNC: '. CREATE_NEW_CONSOLE;
CNC: CREATE_NEW_CONSOLE
C:\>perl -Mwin32::process -Mstrict -e "print 'CNC: '. CREATE_NEW_CONSOLE;
Bareword "CREATE_NEW_CONSOLE" not allowed while "strict subs" in use at -e line 1.
Execution of -e aborted due to compilation errors.
C:\>perl -MWin32::Process -e "print 'CNC: '. CREATE_NEW _CONSOLE;
CNC: 16
You could just place your platform specific code inside of an eval{}, and check for an error.
BEGIN{
eval{
require Win32::Process;
Win32::Process->import(qw'CREATE_NEW_CONSOLE');
};
if( $# ){ # $# is $EVAL_ERROR
# Unix code here
}
}

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